Effect of nutrient management on yield of Bt cotton under rainfed condition in North Saurashtra agro climatic zone

The field experiment carried out to study the effect of nutrient management on seed cotton yield of Bt. Cotton and economics under rainfed condition at Dry Farming Research Station, Junagadh Agricultural University, Jamkhambhalia, Gujarat during Kharif 2011-12 to 2015-16. The experiment was laid out in randomized block design with 9 different treatments comprising of T1 - 80 kg N/ha, T2 - 80 kg N/ha + 20 kg P2O5/ha + 40 kg K2O/ha + 20 kg S/ha, T3 - 80 kg N/ha + 20 kg P2O5/ha + 40 kg K2O/ha + 40 kg S/ha, T4 - 80 kg N/ha + 20 kg P2O5/ha + 80 kg K2O/ha + 20 kg S/ha, T5- 80 kg N/ha + 20 kg P2O5/ha + 80 kg K2O/ha + 40 kg S/ha, T6 - 80 kg N/ha + 40 kg P2O5/ha + 40 kg K2O/ha + 20 kg S/ha, T7 - 80 kg N/ha + 40 kg P2O5/ha + 40 kg K2O/ha + 40 kg S/ha, T8 - 80 kg N/ha + 40 kg P2O5/ha + 80 kg K2O/ha + 20 kg S/ha, T9 - 80 kg N/ha + 40 kg P2O5/ha + 80 kg K2O/ha + 40 kg S/ha, replicated thrice. On the basis of pooled results, maximum values of all the attributes like plant height, number of branches per plant and number of bolls per plant of cotton crop were recorded with treatment T9 (80-40-80-40 NPKS kg/ha).The significantly higher seed cotton yield (1798 kg/ha) and stalk yield (3536 kg/ha) of cotton were recorded under treatment T9 (80 kg N/ha + 40 kg P2O5/ha + 80 kg K2O/ha + 40 kg S/ha) in pooled results. Whereas, lower seed cotton yield (1452 kg/ha) and stalk yield (2569 kg/ha) of cotton were recorded under T1 (80 kg N/ha). The highest total income (Rs. 80905/ha) was also obtained with application of 80-40-80-40 NPKS kg/ha (T9). The pH, EC and organic carbon content of soil were remain unaffected due to different treatments. Significantly higher values of available status of phosphorus, potassium and sulphur in soil were recorded with treatment T9 (80-40-80-40 NPKS kg/ha).